<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div {
            width: 100px;
            height: 100px;
            background: red;
            -webkit-transition: 1s; /*Chrome、safari*/
            -moz-transition: 1s; /*Firefox*/
            -ms-transition: 1s; /*IE,意义不大*/
            -o-transition: 1s; /*Opera*/
            transition: 1s; /*标准*/
        }

        div:hover {
            width: 200px;
            height: 200px;
            background: blue;
        }
    </style>
</head>
<body>
<!--圆角、文字阴影、盒模型阴影、动画、旋转-->
<!---->
<div></div>
</body>
</html>